Sodium

Sodium

Sodium is the major cation in ECF. Sodium performs many functions:

• It maintains the osmotic pressure and concentration of ECF, acid-base balance, and water balance.
• It contributes to nerve conduction and neuromuscular function.
• It plays a role in glandular secretion.

Don’t sweat it

Sodium replacement is necessary in conditions that rapidly deplete sodium, such as anorexia, excessive loss of GI fluids, and excessive perspiration. Diuretics and tap water enemas can also deplete sodium, particularly when fluids are replaced by plain water.

The salt flats

Sodium also can be lost in trauma or wound drainage, adrenal gland insufficiency, cirrhosis of the liver with ascites, syndrome of inappropriate antidiuretic hormone, and prolonged I.V. infusion of dextrose in water without other solutes.

Calling all chlorides

Sodium is typically replaced in the form of sodium chloride.

Pharmacokinetics

Oral and parenteral sodium chloride are quickly absorbed and distributed widely throughout the body.

Metabolism and excretion

Sodium chloride isn’t significantly metabolized. It’s eliminated primarily in urine but also in sweat, tears, and saliva.

Pharmacodynamics

Sodium chloride solution replaces deficiencies of the sodium and chloride ions in the blood plasma.

Pharmacotherapeutics

Sodium chloride is used for water and electrolyte replacement in patients with hyponatremia from electrolyte loss or severe sodium chloride depletion.

A welcome infusion

Severe symptomatic sodium deficiency may be treated by I.V. infusion of a solution containing sodium chloride.

Drug interactions

No significant drug interactions have been reported with sodium chloride. (See Adverse reactions to sodium.)

Warning!

Adverse reactions to sodium

Adverse reactions to sodium include:

• pulmonary edema (if given too rapidly or in excess)
• hypernatremia
• potassium loss.